System.Tuple`2 suggests me about the "anonymous type" behind the Tuple class, but I can't find what going on behind the scene, and how to fix this issue.

Edit: Sorry, my bad, I just discovered that our main project is set to .NET 3.5, and it uses Tuple from a custom reference (System.ComponentModel.Composition), and test project is using .NET 4.0, and it use .NET's Tuple class. I don't know how this version-inconsistent come to our solution, but I had to switch to another workaround. instead of use Tuple.

System.Tuple2 has nothing to do with anonymous types, it just indicates the one of classes named Tuple` which has two generic parameters (in same fashion as e.g. System.Collections.Generic.List1, System.Collections.Generic.Dictionary2 etc). System.Tuple is, according to MSDN ( msdn.microsoft.com/en-us/library/system.tuple.aspx ), a static class, so there could be no instances of System.Tuple, and thus the error you're facing is confusing at least. Hope this helps in some way.
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penarturFeb 15 '12 at 10:25